Years ago the block heater in my 1955 burned out. Since I'd quit farming and didn't use the tractor during the winter i kinda forgot about it. My son started the farming operation up again, and I figured it might be a good idea to replace that burned out element. Been as low as -25 to -30 here that last couple of weeks. Sure glad I did replace the thing! Leave it plugged in 24/7 just in case. Have needed the tractor a couple of times already where it never would have started without the block heater.